This invention relates to a noise eliminating element which can be used as a sound quality improving element, electronic image quality improving element, etc. and an electrical circuit having the same.
Noises in electrical circuits include electromagnetic noises introduced from alternate current power sources, external noises such as from eletrical discharges, thunder or automobile ignition plugs, and internal noises which take place through complicated behaviors such as thermal motion or scattering of electrons in electronic parts such as resistors or semiconductor elements, etc.
As techniques for eliminating and preventing these noises, there have been known in the state of the art, a noise filter, noise-cut-off transformer, reduction of thermal noises by cooling, electromagnetic shielding, etc. However, these noise eliminating, preventing techniques of the prior art involve such problems as limited effective noise frequency, distortion of original signals, etc.
In the prior art, for the output circuit of an electromagnetic device, a coil has been generally employed. By sending an output signal current through the coil, the magnetic field generated in the coil changes the output signal. The modified signal is finally converted to a desired form such as an electronic acoustic sound wave, an electronic image display, recording display, etc. In the prior art, in such electromagnetic devices, it has been difficult to obtain a noiseless output faithful to the input signal.
In the output circuit of the electromagnetic device of the prior art, particularly near a null point of the current where the current polarity of the output signal is abruptly reversed, an electromagnetic induction voltage through interference with the coil or the external magnetic field is generated, and consequently a noise current is generated. For this reason, the normal output signal receives disturbance, and by repetition of such disturbance, irregular standing wave noises will be generated and grown in the output signal, particularly at a current value close to zero.
Also, within electromagnetic devices, in addition to coils, there are a large number of electrical, electronic parts connected and built in, such as transformers, resistors, condensers, semiconductor elements. The output current including the above standing wave noise is also affected by electrical characteristics such as inductance, conductance, capacitance, etc. possessed by these parts, and the characteristics in material properties such as thermal noise or scattering of electrons. As a result, the standing wave noise of the current particularly around zero current generates more noise with greater energy through interference with the standing wave noise.
Since these standing wave noises overlap the normal output signal which should be inherently faithful to the input signal, they cannot practically convert the input signal faithfully. Such noises in electromagnetic devices make the conversion of input signals to acoustic, image, data recording, etc. incorrect and indistinct, thereby losing scientific value, artistic nature, and also irritating excessively visual and auditory nerves of man, thus creating harm in social environments, artistic cultures, mental hygiene and scientific techniques.